Squint Scale Curtiss Model K Aero I4

[RReid]

Thank you both, Per and CNR!

[bent]

Wow, coming along nicely Ron!  Still wondering how you balance the spring forces to make the push-pull rods work on the valve train.   

[RReid]

Thanks Bent!

As far as those springs goes, the main thing is that the pull-down springs have to be stronger than the valve springs, but not so strong as to add needless pullrod/cam friction. The springs I have in there now seem to work, as least up to a few hundred rpm as applied by my lathe. Whether they'll float at higher rpm remains to be seen. It could end up being a trial and error thing to get right. In the worst case, a real bugger.

[RReid]

My ebay sourced 40 tooth gear arrived yesterday. The first step was to get it loctited to an arbor rod, then leave it overnight to cure. Part of that rod will also serve as a sleeve, to reduce the bore from 1/4” to 3/16” to match the camshaft. This morning I turned the hub down to 3/8”, then turned the gear around, clamped the hub in a 3/8” collet, parted of the excess rod, and drilled/reamed to 3/16”
 



The gear was then moved to the rotary table on the mill, and six 1/4” “lightening” holes were drilled using and end mill. Since I was drilling out near the edge, I used the “support” seen in the photo, just for comfort. I do still have to drill and tap the hub for the set screws. It will go back on the arbor rod for that.


I've also continued to work on the magneto, which is now mounted and almost complete, short of a couple of minor detail jobs left to do, including cutting those two lower terminal lugs to length.


And here's the gear train in place, though not fully fastened. The gears turn and mesh smoothly, so I'm happy!

[Kim]

Very nice looking gears, Ron! 

Kim

[Admiral_dk]

Very essential part on a Four-Stroke Engine and it just looks right there in Situ 

You are certainly getting closer to first Pop Ron 

Per

[RReid]

Thanks Kim!
Thanks Per! Maybe if I sneak up on it slowly enough, I can catch the first pop gremlins off guard...

[RReid]

With the gears in place, I was able to run a slow speed mechanism test under lathe power. I did run it a bit faster later, successfully, but I don't want to get too carried away at this point.
<a href="https://www.youtube.com/watch?v=ZEPYYrDkAvc" target="_blank">http://www.youtube.com/watch?v=ZEPYYrDkAvc</a>

[Dave Otto]

Great progress Ron!
Still quietly following along and not commenting nearly enough.

Dave

[90LX_Notch]

Ron-

Exactly what Dave said.  I check in everyday hoping for an update.  I love this build.

-Bob

[cnr6400]

  The engine looks fantastic in motion! 

[fumopuc]

Hi Ron,
a very interesting motion, pleasure to watch.

[kuhncw]

Very nice work, Ron.

[RReid]

Dave, Bob, CNR, Achim, Chuck – Thank you all very much! The interest and support is much appreciated!

[bent]

As others said, that video is memsmerizing.  Nice closeup on the valve train, and great explanation.  Can't wait to see it run!